This page shows average OMI HCHO vertical columns for all
months between 10/2004 and 09/2009. A background correction
based on monthly average values over the sourthern remote
Pacific has been applied to all total column values in order
to remove the steady increase in HCHO background values
observed over the OMI life time. Data have been screened for
clouds, rejecting any pixels with cloud cover above 40%.
Images show OMI HCHO data from Collection 3. Click on an image
to enlarge.

Corresponding observations of OMI CHO-CHO (glyoxal)
vertical columns can be found
here.